6. Which of the following diseases is NOT caused by bacterial infection?
a. Anthrax
b. Tetanus
c. Shingles
d. Syphilis
Shingles is the disease not caused by bacterial infection, as it results from reactivation of the varicella-zoster virus, unlike the others triggered by specific bacteria.
Option Analysis
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Anthrax (Option a): Caused by the spore-forming bacterium Bacillus anthracis, which produces toxins leading to severe illness, often through skin contact, inhalation, or ingestion from infected animals or soil.
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Tetanus (Option b): Results from Clostridium tetani bacteria, whose spores enter wounds and release tetanospasmin toxin, causing muscle spasms; common in contaminated injuries.
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Shingles (Option c): Triggered by the varicella-zoster virus (same as chickenpox), reactivating in nerve cells to cause painful rash, especially in those with weakened immunity; not bacterial.
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Syphilis (Option d): Caused by the spirochete bacterium Treponema pallidum, spreading via sexual contact or skin breaks, progressing through stages if untreated.
Key Differences in Pathogens
| Disease | Pathogen Type | Specific Agent | Transmission Mode |
|---|---|---|---|
| Anthrax | Bacterial | Bacillus anthracis | Animal products, spores |
| Tetanus | Bacterial | Clostridium tetani | Wounds, soil contamination |
| Shingles | Viral | Varicella-zoster virus | Reactivation (no direct spread) |
| Syphilis | Bacterial | Treponema pallidum | Sexual contact, mucous membranes |
This MCQ tests microbiology basics in exams like CSIR NET, emphasizing pathogen distinction for bacterial vs viral diseases.
